The present invention relates to a sample handling system for automatically testing samples with a diagnostic module. More particularly, the invention relates to a sample handling system that includes a robotic arm for moving a carrier with a plurality of sample tubes from a loading rack to a predetermined location to be tested by a diagnostic analyzer and then returning the carrier to the loading rack for unloading or retesting.
In the past, sample handling systems had a single path carrier that would stop at specified locations as desired for testing. In these single path systems, if retesting or preemptive prioritization of a sample were required, the tube would have to travel around the entire module system to be tested or retested. This resulted in either significant delay in testing and retesting or very complex expensive carrier routing mechanisms.
An example of a single path sample handling device is disclosed in U.S. Pat. No. 5,876,670 to Mitsumaki. In Mitsumaki, a sample carrier, holding a plurality of test tubes, is transferred to the analyzer modules by a transporting belt driven by a motor. All the sample carriers on the transporting belt pass through the sampling position for the first analyzer module and must be transferred to a receiving position to reach the sampling position for the second analyzer module. When a sample needs to be retested, then the operator returns the sample carrier to the beginning of the transporting belt. An urgent sample supply portion is provided on one end of the belt near the sample supply portion, allowing urgent sample racks to be processed before the general racks. In Mitsumaki, the sample handling system processes samples sequentially along the transporting belt and does not automatically retest samples.
Another example of a prior sample handling system is disclosed in U.S. Pat. No. 5,665,309 to Champseix et al. The Champseix et al. device comprises a holding rack for a plurality of test tubes; a sampling station for sampling the contents of a tube; and a gripping device for withdrawing a tube from a selected position on the rack, bringing the tube to the sampling station and returning the tube back to its selected position. The gripping device moves the individual tubes from a rack to the sampling station. However, the Champseix et al., sample handling device does not disclose a method for automatically retesting samples or processing stat samples.
U.S. Pat. No. 5,260,872 to Copeland discloses an automated testing system for the quality testing of production samples, comprising a loading station for receiving a test tube rack containing a plurality of test tubes; a pipetting station; a bead-drop station; and a robotic device having an arm adapted to pick up a test tube rack from the loading station, move the rack to the pipetting station so the fluids can be pipetted into the test tubes; move the rack to the bead-drop station; and return the rack to the loading station in accordance with a computer program. When the Copeland test tube rack is returned to the loading station the tubes may be removed and disposed of and the rack is then loaded with a fresh set of test tubes. The Copeland system does not accommodate for automatic retesting or testing of stat samples.
The present invention is a random sample handling system for moving samples to and from a diagnostic module for automatic testing and retesting. The random handling system includes a loading rack for receiving a plurality of carriers. The carriers can include several tubes filled with samples. In a preferred embodiment, the sample carriers are arranged in a stationary linear array on a loading rack positioned in front of the diagnostic modules. The operator may load the carriers individually or in trays for convenient handling of multiple carriers. Individual carrier slots are provided for loading high priority or stat samples that require immediate processing.
A robotic device is provided to transport the carriers to and from the loading rack and to and from a carrier positioner adjacent the diagnostic module(s). The robotic device has an arm, which is controlled by a programmable computer, moving the carriers as required for testing and retesting. The system includes software that allows users to flexibly configure rules or criteria for retesting samples. These rules can also be utilized to change to another type of test depending on the results of a previous test. This can be a very cost effective approach that when utilized minimizes operator involvement in real time. The system also includes a software capability that can suspend the operation of the sampler handler in the event the user decides to change the test request(s) for a particular sample after loading the carrier.
The carrier positioner is located adjacent a diagnostic module for positioning the carriers so the samples selected for testing can be aspirated by a probe. The positioner includes a carriage connected to a lead screw driven by a stepping motor in response to commands from the programmable computer. In a preferred embodiment, the carrier positioner can accommodate at least two carriers, allowing the processing module to test one carrier while the transporter loads another carrier onto the positioner to maintain the system throughput.
A barcode reader is provided to read carrier and sample identification. A bar code reader in the system reads bar coded labels attached to the carriers and the sample tubes as the robotic device passes the carriers by the reader.
Only one robotic device and barcode reader are required for the present system, regardless of size. The invention can be dynamically configured for variable queue sizing depending on the user""s particular workload. Additionally, the total capacity of the system can be changed based on peak loading requirements that vary across testing segments in the laboratory.
In operation, the robotic arm picks up a carrier from the loading rack and travels past the bar code reader to identify the carrier and samples. Tests previously programmed in the computer are assigned to each tube in the carrier. The robotic arm delivers the carrier to be tested to the carrier positioner. The positioner is controlled by the computer to move the carrier to a predetermined location adjacent a pipetter on the diagnostic module. The pipetter aspirates samples from the tube for testing. When the tests are completed on all the tubes in the carrier, the robotic arm loads the carrier and returns the carrier to its designated location in the loading rack. While the tubes of one carrier are being aspirated, a second carrier can be moved to the carriage.
The sample handling system can include more than one diagnostic module. For example in one preferred embodiment, the sample handling system includes two diagnostic modules, a clinical chemistry test module and an immunoassay module. A carrier positioner is provided for each diagnostic module in the system.
An object of the present invention is to provide a modular random sampling system that can be adapted to a variety of diagnostic modules. The present sample handling system is modular and scalable to different sizes of processing modules and may be used for single or multiple module systems. The system provides random access to sample carriers on the loading rack. This random access capability allows the system to access and process high priority samples rapidly. This capability also allows the system to balance the workload of multiple processing modules with different throughput capabilities. After samples are processed initially, the sample carriers are returned to their slots in the loading area and then accessed again when the initial testing is complete to provide automated retest capability. This automated retest capability does not require any additional intervention by the operator. Random access assures the samples to be retested can be processed in the shortest possible time. The system is mechanically simple, which minimizes system cost and maximizes system reliability. The present system is self-contained and can be assembled and tested independently of the processing modules for ease of manufacture and installation in the field.
Another object of the present invention is to provide a system that processes samples for testing and retesting in a faster time and with more reliability than previous handling systems. Additionally, an object of the present invention is to provide a sample handling system that provides faster processing of high priority samples while maintaining throughput of routine test samples.
A further object of the present invention is to provide a system having a robotic means for moving a carrier with a plurality of test samples from a loading rack to a sample testing area and returning the carrier to the loading rack and having a programmable computer for (1) controlling the robotic means, (2) selecting carriers for testing based on predetermined priority, (3) achieving positive identification of the carriers and samples, and (4) identifying a breach of positive identification when an access door has been opened or a carrier has been removed prematurely.
Additional advantages of the invention will be realized and attained by the apparatus and method particularly pointed out in the written description and claims hereof, as well as from the appended drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention claimed.